I was wondering what the rules are regarding wanting to upgrade, either to First Class or Standard Premium or whatever...
Which operator are you travelling with, what journey is it, and what day of the week is it?
I had assumed (possibly incorrectly) that on an ex InterCity service, you could take a seat and pay when the guard came round (noting that if you have a ticket that can't be upgraded (are there any?), you'd buy a new ticket.
That's not true of all services that currently exist that used to be operated by BR InterCity (notwithstanding the difficulty of establishing which services are direct descendants)
On other services, presumably you could upgrade if you speak to the guard BEFORE taking your seat.
But on DOO services, such as Thameslink, you MUST have a First Class ticket before boarding. And, yes, Thameslink is a bad example as you'd just sit in the declassified bit at the back.
I sometimes want to upgrade, just wondered if this is the right approach.
It's nothing to do with the operation of the train; some trains are DOO but have staff whose responsibilities include checking tickets (e.g. on Southeastern High Speed, Lumo, Scotrail and others, with a range of job titles), but these services generally do not convey First Class accommodation.
Similarly, there are trains which have Guards, but the Guards are non-commercial in nature (e.g. SWR), but again these generally do not convey First Class accommodation (but are there any SWR services with non-commercial Guards which do convey First Class, does anyone know?)
Even if a commercial Guard is present, this doesn't necessarily mean that an authorised collector cannot issue a Penalty Fare.
At weekends, the rules may be further relaxed, as Weekend First upgrades may be available; this may depend on operator / route.
It may also depend on what type of ticket is held, for example on weekdays when Weekend First isn't available, a passenger holding a
single or return ticket can still upgrade to the lowest possible fare on LNER, but - last time I read the rules (this may have changed) - a s
eason ticket holder could be penalised to the extent of being charged the full fare, as if no ticket was held.
I don't know if you would classify trains operated by GTR under the "Gatwick Express" brand as "former InterCity" services (they were IC under BR, but did not extend to Brighton), but these trains used to offer the full range of fares on board, but are now Penalty Fare trains. They do not have Guards, but do have an OBS, but I'm not sure if the OBS would charge a Penalty Fare, or if a Penalty Fare would only apply if a revenue protection officer/inspector joined the train (I'm sure someone familiar with the route would know the answer to this).